Zbigniew Kwias

Elevated Blood Active Ghrelin and Unaltered Total Ghrelin and Obestatin Concentrations in Prostate Carcinoma

Purpose: Ghrelin and its functional receptor are highly expressed in prostate cancer (PC) and ghrelin may activate proliferation of PC cell lines. This study was therefore designed to characterize the association between serum acylated and total ghrelin, and obestatin levels in patients with benign prostate hyperplasia (BPH) and PC. Methods: Blood serum concentrations of active and total ghrelin and obestatin were estimated by EIA methods. Results: Serum level of active ghrelin in PC was significantly higher compared to control and BPH groups. On the other hand, concentrations of total ghrelin and of obestatin did not differ between studied groups of patients. In the control group the ratio of active to total ghrelin concentrations amounted to 0.16, and it was similar in BPH (0.14), while it was notably elevated in PC (0.42). Also the ratio of active ghrelin to obestatin concentrations was higher in the group with PC than in the control and BPH groups. In all studied groups, the ratio of total circulating ghrelin to obestatin was similar. Conclusions: Obtained results suggest the link between elevated blood active ghrelin and PC, and we cannot exclude that elevated circulating active ghrelin may affect growth of malignant prostatic tissues.

FUT11 as a potential biomarker of clear cell renal cell carcinoma progression based on meta-analysis of gene expression data

In this paper, we provide a comprehensive summary of available clear cell renal cell carcinoma (ccRCC) microarray data in the form of meta-analysis of genes differentially regulated in tumors as compared to healthy tissue, using effect size to measure the strength of a relationship between the disease and gene expression. We identified 725 differentially regulated genes, with a number of interesting targets, such as TMEM213, SMIM5, or ATPases: ATP6V0A4 and ATP6V1G3, of which limited or no information is available in terms of their function in ccRCC pathology. Downregulated genes tended to represent pathways related to tissue remodeling, blood clotting, vasodilation, and energy metabolism, while upregulated genes were classified into pathways generally deregulated in cancers: immune system response, inflammatory response, angiogenesis, and apoptosis. One hundred fifteen deregulated genes were included in network analysis, with EGLN3, AP-2, NR3C1, HIF1A, and EPAS1 (gene encoding HIF2-α) as points of functional convergence, but, interestingly, 610 genes failed to join previously identified molecular networks. Furthermore, we validated the expression of 14 top deregulated genes in independent sample set of 32 ccRCC tumors by qPCR and tested if it could serve as a marker of disease progression. We found a correlation of high fucosyltransferase 11 (FUT11) expression with non-symptomatic course of the disease, which suggests that FUT11s expression might be potentially used as a biomarker of disease progression.

ZFP91—A Newly Described Gene Potentially Involved in Prostate Pathology

In search for novel molecular targets in benign prostate hyperplasia (BPH), a PCR Array based screening of 84 genes was performed. Of those, expression of ZFP91 (ZFP91 zinc finger protein) was notably upregulated. Limited data concerning the function of ZFP91 product show that it is a potential transcription factor upregulated in human acute myelogenous leukemia and most recently found to be the non-canonical NF-κB pathway regulator. In order to test this finding on a larger number of samples, prostate specimens were obtained from patients undergoing adenomectomy for BPH (n = 21), and as a control, from patients undergoing radical cystectomy for bladder cancer (prostates unchanged pathologically, n = 18). Similar studies were performed on cultured human prostate cancer cell lines: LNCaP, DU145, 22Rv1, PC-3; as well as normal prostate epithelial cells—PrEC. Methods employed included: Human Obesity PCR Array (Qiagen), QPCR and Western blotting. QPCR studies confirmed significant overexpression of ZFP91 in BPH samples. On a protein level, however, comparison between normal and BPH prostates revealed insignificant differences. As for prostate cell lines examined, all expressed ZFP91 mRNA. Western blotting analysis showed markedly higher protein levels of ZFP91 in all cancer cell lines in comparison with normal (PrEC) cells. In conclusion, the upregulated ZFP91 mRNA in BPH, not accompanied by parallel changes in ZFP91 protein levels, together with ZFP91 protein abundance in prostate cancer cell lines suggest ZFP91 involvement in these prostate diseases.

Hormone therapy in combination with radiotherapy in the treatment of prostate cancer: why and in which group of patients?

In recent years, significant development in the treatment of prostate cancer has taken place. One of the most documented methods of treatment in patients characterised by a high risk of progression is a combination of radiotherapy (RT) with long-term hormone therapy (HT). In this group of patients, neither RT alone nor HT alone allows satisfactory outcomes to be achieved, and therefore as monotherapy they are not recommended as optimal methods of treatment. In this review, we summarise arguments for combining radiotherapy with hormonal therapy in high-risk prostate cancer, with an emphasis on the results of phase III trials.

What is the possible role of PSA doubling time (PSADT) and PSA velocity (PSAV) in the decision-making process to initiate salvage radiotherapy following radical prostatectomy in patients with prostate cancer?

This article is an attempt to present a contemporary view on the role of the kinetics of PSA levels as defined by PSA doubling time (PSADT) and PSA velocity (PSAV) in the decision-making process to initiate salvage radiotherapy in patients with prostate cancer after radical prostatectomy (RP). The dynamics of the rise of PSA levels may be an early endpoint parameter, preceding the diagnosis of distant metastasis or death due to prostate cancer based on a single PSA determination. Thus, it seems reasonable to include the kinetics of PSA levels, apart from single PSA determination, in the decision-making algorithm. In a group of patients after RP, PSADT might be an early endpoint that could replace cause-specific survival rate as a late endpoint. PSADT allows distinguishing subgroups of patients at high risk of distant metastases and death, which in turn may lead to a change in the further treatment strategy. Therefore, patients with short PSA doubling time should become a subgroup, in which hormonal therapy should be considered. To date, there is no unanimous consent to accept the criteria of assessment of the dynamics of PSA levels as determinants of treatment in case of recurrences following RP. However, a number of non-randomized clinical trials in patients after RP suggest it would be useful to include these parameters in the decision-making process. For instance, a relationship was found between increased PSA velocity (>2 ng/mL/year) before initiation of oncological treatment and increased (12-fold) risk of death. A number of well-documented retrospective analyses show that PSADT is one of the most important parameters to describe the disease aggressiveness. It has to be stressed that single determination of PSA levels is much less precise in terms of describing the biological aggressiveness of prostate cancer than PSADT. Of course, the question regarding the need to include the PSA levels kinetic parameters as crucial elements of patient management algorithms can be answered in a definitive manner only by randomized clinical trials.

The use of luteinizing hormone-releasing hormone analogues is still an indispensable element of therapy in castrate-resistant prostate cancer.

Metastatic prostate cancer, which shows progression despite castration testosterone levels, was previously defined as hormone-refractory. This definition has recently been changed to the one presently used – castrate-resistant prostate cancer. Numerous fundamental studies have provided evidence that the development of hormone-refractory prostate cancer is constantly dependent on the concentration of androgens. The aim of the metastatic castrate-resistant prostate cancer (mCRPC) treatment is currently to obtain the lowest possible androgen concentration. The effectiveness of such management has been proven by the results of clinical studies on the latest hormonal and chemotherapeutic medications. In the last two decades, new effective chemotherapeutics have become available on the market: abiraterone, enzalutamide, docetaxel, cabazitaxel, zoldronic acid, denosumab and alpharadin They significantly contribute to extending patients’ survival and to improving their quality of life. Therefore, the question arises whether using luteinizing hormone-releasing hormone (LHRH) analogues is still a necessary element of the therapy. A detailed analysis of study regimens involving the above-mentioned medications and of available publications supports the view that LHRH analogues are the basic strategy in the treatment of patients with mCRPC. All clinical trials evaluating new therapies still followed the principle of obtaining castration testosterone levels as a result of using LHRH analogues simultaneously with the new medications.

Genetic characterization of Polish ccRCC patients: somatic mutation analysis of PBRM1, BAP1 and KDMC5, genomic SNP array analysis in tumor biopsy and preliminary results of chromosome aberrations analysis in plasma cell free DNA

Background Mutation analysis and cytogenetic testing in clear cell renal cell carcinoma (ccRCC) is not yet implemented in a routine diagnostics of ccRCC. Material and methods We characterized the chromosomal alterations in 83 ccRCC tumors from Polish patients using whole genome SNP genotyping assay. Moreover, the utility of next generation sequencing of cell free DNA (cfDNA) in patients plasma as a potential tool for non-invasive cytogenetic analysis was tested. Additionally, tumor specific somatic mutations in PBRM1, BAP1 and KDM5C were determined Results We confirmed a correlation between deletions at 9p and higher tumor size, and deletion of chromosome 20 and the survival time. In Fuhrman grade 1, only aberrations of 3p and 8p deletion, gain of 5q and 13q and gains of chromosome 7 and 16 were present. The number of aberrations increased with Fuhrman grade, all chromosomes displayed cytogenetic changes in G3 and G4. ccRCC specific chromosome aberrations were observed in cfDNA, although discrepancies were found between cfDNA and tumor samples. In total 12 common and 94 rare variants were detected in PBRM1, BAP1 and KDM5C, with four potentially pathogenic variants. We observed markedly lower mutation load in PBRM1. Conclusions Cytogenetic analysis of cfDNA may allow more accurate diagnosis of tumor aberrations and therefore the correlation between the chromosome aberrations in cfDNA and clinical outcome should be studied in larger cohorts. The functional studies on in BAP1, KDM5C, PBRM1 mutations in large, independent sample set would be necessary for the assessment of their prognostic and diagnostic potential.

Potential protective role of Grainyhead‐like genes in the development of clear cell renal cell carcinoma

The involvement of Grainyhead‐like (GRHL) transcription factors in various cancers is well documented. However, little is known about their role in clear cell renal cell carcinoma (ccRCC). We discovered that the expression of two of these factors—GRHL1 and GRHL2—are downregulated in ccRCC samples, and their expression is correlated with the expression of VHL gene. This suggests a functional link between the GRHL transcription factors and one of the best known tumor suppressors. Although the GRHL genes are not mutated in ccRCC, some of the single nucleotide polymorphisms in these genes may indicate an increased risk of ccRCC development and/or may allow to assess patients’ prognoses and predict their responses to various forms of therapy. Silencing of GRHL2 expression in non‐tumorigenic kidney cell line results in increased cell proliferation, increased resistance to apoptosis, as well as changes in the levels of selected proteins involved in the pathogenesis of ccRCC. These changes support the potential role for GRHL2 as a suppressor of ccRCC.